Answer:
Thus the time taken is calculated as 387.69 years
Solution:
As per the question:
Half life of
= 28.5 yrs
Now,
To calculate the time, t in which the 99.99% of the release in the reactor:
By using the formula:

where
N = No. of nuclei left after time t
= No. of nuclei initially started with

(Since, 100% - 99.99% = 0.01%)
Thus

Taking log on both the sides:


t = 387.69 yrs
Answer:
The average velocity of the sled is vavg = s/t.
Explanation:
Hi there!
The average velocity is calculated as the traveled distance over time:
vavg = Δx/Δt
Where:
vavg = average velocity.
Δx = traveled distance.
Δt = elapsed time.
We already know the traveled distance (s) and also know the time it takes the sled to travel that distance (t). Then, the average velocity can be calculated as follows:
vavg = s/t
Have a nice day!
Answer:
Option (D) is correct.
Explanation:
The balloon lands horizontally at a distance of 420 m from a point where it as released.
Velocity of air balloon along +X axis =10 m/s
velocity of ball=4 m/s along + X axis
the velocity of balloon gets added to the velocity of ball. So the resultant velocity of the balloon=10+4 = 14 m/s
time taken= 30 s
The distance traveled is given by d= v t
d= 14 (30)
d= 420 m
Thus the balloon lands horizontally at a distance of 420 m from a point where it as released.
Frictional forces act in the direction opposite to the MOTION. That direction could be the same OR opposite to applied force.
-- If you push a loaded heavy wagon from behind, trying to get it going faster, friction is acting against you, opposite to your force.
-- If you push a loaded rolling heavy wagon from in front, trying to make it slow down, friction is acting with you, in the same direction as your force.
-- Opposite to the motion both times.
Answer:
The sweet food changed because the molecules were able to move fast enough to overcome the attraction between them with its molecules now moving away from each other.
Explanation:
We are told that the sweet food has a strong attraction between its molecules, and the sour food has a weak attraction between its molecules.
This means that the molecules in the sweet food would be moving at a faster rate than in the sour food because of the strong forces of attraction. Therefore, the molecules in the sweet food would be moving far away from each other hence the change of phase.